After trying to find a ignition live feed in the engine bay last Sunday for my next project, which involved a lot of door opening and closing and ignition on and off it seems my battery is no longer up to the task As I found out on Wednesday evening when I went out to test the LED halos and found the door wouldn`t open, only with the key, which I found odd. I set up my test wire to the battery and tested all the halos, everything was fine until I went to close the door and found that the window had gone back up and the door was locked.
The fob wouldn`t work so I changed the battery (twice) to no avail and nothing else seemed to work and only when I tried the seat adjustment and the seat moved a few millimetres and stopped did it occur to me it was actually the car battery and not the fob that was the issue.
Are there any precautions I need to take before hand as I have read quite a few cases where the fob isn`t detected after a battery change or other strange behaviour. One thing I hate about changing the battery on newer cars is having to reset everything afterwards.